Dear Bougart:
Yes you can change to EB-2,or NIW. Sometimes, INS Officers, they write on which category you will fit if you are not fit for EB-1. I heard from my friend, that,his case denied on EB-1 basis, but Ins officers wrote to submit on EB-2 category.
One thing if RFE they write like that, you case is ok, but if you restart it will start from scratch. Don't worry, submiit your RFE as soon as possible, you might have 12 weeks, I mean October 1st( before that you have to submit).
if you are from INDIA, qualified CSIR, GATE, That si VERY VERY IMP. if you are doing postdoc, tell your boss he hired you by selecting among all candidates world wide.
but it looks very tough. Believe in your luck. You will get through.
GOOD luck Bougart.